"driving" in the left lane. YES it's illegal.

"Often the roads are just crammed with far more vehicles than the road was designed."

This is very true, and a real issue in urban areas. And much of it is driver obliviousness I believe: they are mostly unaware of what is going on around them. Driving is a task to be done, and many seem to feel they can multi-task while performing this task. Unfortunately they're wrong.